When a woman stands with her legs together, but there is triangular gap between her thighs right under her butt. Most notable when she is wearing a bathing suit or short shorts. Refers to the fact that air can flow between her thighs.

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A man asking a women that is giving him head to lick his ass,and when she does so pretend that he likes it but he is just struggling to pull a fart,and in the end farts in her face to give her a taste of that "fresh air"